PROJECT SUMMARY Rates of sexual assault are alarmingly high, and alcohol is consistently implicated in the majority of these assaults. Despite well-intentioned prevention efforts, this pandemic continues unabated, warranting the development of novel and innovative approaches to the reduction of sexual aggression. The objective of the proposed research is to evaluate the efficacy of two brief online emotion regulation (ER) interventions for reducing alcohol-related sexual aggression (SA) in heavy episodic drinking (HED) young men with an SA history. Extant research suggests that ER difficulties are associated with both alcohol consumption and aggressive behavior. Despite the potential prevention utility of improving sexually aggressive men?s ER skills in order to reduce their alcohol-related SA, this approach has yet to be explored. Because full-scale, longitudinal randomized clinical trials are quite resource-intensive, this project proposes to use innovative proximal change experiment methods which enable researchers to test intervention effects and examine specific mechanisms of behavior change before conducting more resource-intensive clinical trials. Using a sample of HED men aged 21-30 who have a history of SA perpetration, the proposed study will evaluate the effects of two brief online ER interventions ? cognitive restructuring and mindfulness ? on men?s ER during an SA-related analogue. Additionally, these effects will be evaluated during both sober and intoxicated states through a laboratory- based alcohol administration experiment. After completing a screening procedure, participants (N = 210) will attend a laboratory session that includes an assessment of relevant background factors. Participants will then be randomly assigned to the cognitive restructuring ER intervention, the mindfulness ER intervention, or an attention control group. After receiving the intervention and practicing the targeted ER skill, participants will then be block randomized (by intervention condition) to receive either no alcohol or a high alcohol dose (target peak BAC = .08%). They will then complete a proximal change protocol that includes 1) implementing the ER skill that they learned in the intervention and 2) completing a SA analogue that assesses their SA-related emotions and intentions through the use of a hypothetical sexual scenario. We will examine both main and interactive effects of intervention condition and experiment beverage condition on dependent measures, as well as the mediation of these effects through ER processes. Related background factors (e.g., SA severity) will be explored as moderators of ER intervention efficacy, and differential effects of the two ER interventions will be evaluated. The proposed project offers several significant innovations to alcohol-related SA prevention efforts through: (1) its focus on ER processes as mechanisms of behavior change; (2) its application of two brief online ER interventions that have demonstrated initial promise for men?s SA reduction; (3) its investigation of intervention efficacy during states of acute alcohol intoxication; and (4) its use of cost-effective proximal change methods to evaluate intervention efficacy.